THIS SNOWPACK SUMMARY EXPIRED ON March 27, 2017 @ 9:35 am
Snowpack Summary published on March 25, 2017 @ 9:35 am
Issued by Ryan Lewthwaite -

bottom line:

New snow coupled with strong winds from the SW will load slopes, making human triggered avalanches possible on leeward aspects steeper than 35 degrees. Wind slabs & growing cornices will be the lingering problem for backcountry recreationists. Investigate the snow conditions constatntly in order to have the best awareness of your surroundings. 

Avalanche Character 1: Wind Slab
Wind Slab avalanches release naturally during wind events and can be triggered for up to a week after a wind event. They form in lee and cross-loaded terrain features. Avoid them by sticking to wind sheltered or wind scoured areas.

High winds and rapid loading were witnessed yesterday as this pulse of moisture swept through the BWRA. Gusting to 45 mph, blowing snow made visibility poor, creating drifts and localized wind slabs on NW-N-NE-E-SE aspects. Traveling above or near treeline on slopes steeper than 35 degrees could be prime places to trigger a stiff slab. Conversely snow will be scoured on windward S-SW-W aspects. 

Avalanche Character 2: Cornice
Cornice Fall avalanches are caused by a release of overhanging, wind drifted snow. Cornices form on lee and cross-loaded ridges, sub-ridges, and sharp convexities. They are easiest to trigger during periods of rapid growth from wind drifting, rapid warming, or during rain-on-snow events. Cornices may break farther back onto flatter areas than expected.

Accumulations of wind-driven snow on leeward NW-N-NE-E-SE aspects will create large & irregular overhanging cornices. Cornices suspended over dramatic terrain changes can be hard to estimate where & when failure may occur. If riding in the area of a suspiciously loaded slope on these aspects, error on the cautious side. Without the slopes support cornices can fail & propagate far behind where you may percieve.   

recent observations

Snowpack investigations portrayed 2cm of light new snow on top of a more saturated 20cm from Tuesday's storm activity. Tests included: 2 CT's, ECT, & PST; results were not indicating poor stability. The layer of concern could be the stout melt-freeze crust at 36cm, resulting from last weeks high pressure dominance. This crust was 5cm thick & showed good bonding to the snow bordering it.

weather

Intermittent moisture resides over the BWRA into Monday with patchy snow showers. Colder temperatures & snow accumulations totalling 5-7" above 7000' will dominate the region. 4-6" fell Friday night & was wind scattered across the higher elevations with temps in the high teens. Expect partly cloudy skies & a rise in temperature through the weekend with drying conditions.

Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 8000 ft. to 10000 ft.
  Saturday Saturday Night Sunday
Weather: Mostly cloudy. Scattered snow showers in the morning, then slight chance of snow showers in the afternoon. Partly Cloudy Mostly cloudy. Chance of snow in the afternoon
Temperatures: 36 to 44 deg. F. 20 to 28 deg. F. 40 to46 deg. F.
Wind direction: NA NA NA
Wind speed: Light winds. Gusts up to 25 mph in the morning Light Light winds becoming southwest 10 to 15 mph with gusts to 35 mph in the afternoon
Expected snowfall: 1-2" in. 0 in. 1-2" in.
For above 10000 ft.
  Saturday Saturday Night Sunday
Weather: Mostly cloudy. Scattered snow showers in the morning, then slight chance of snow showers in the afternoon Partly Cloudy Mostly cloudy. Chance of snow in the afternoon
Temperatures: 28 to 36 deg. F. 17 to 23 deg. F. 34 to 40 deg. F.
Wind direction: West Northwest Southwest
Wind speed: 15 to 20 mph. Gusts up to 40 mph decreasing to 25 mph in the afternoon. 10 to 15 mph with gusts to 25 mph in the evening becoming light 10 to 15 mph with gusts to 35 mph increasing to 20 to 30 mph with gusts to 45 mph in the afternoon.
Expected snowfall: 1 in. 0 in. 1 in.
Disclaimer

This snowpack summary applies only to backcountry areas in the Bridgeport Winter Recreation Area. Click here for a map of the area. This snowpack summary describes general avalanche conditions and local variations always occur. This snowpack summary expires in 48 hours unless otherwise noted. The information in this snowpack summary is provided by the USDA Forest Service who is solely responsible for its content.